DIFFUSION OF LONG MOLECULES THROUGH SOLID POLYETHYLENE .2. MEASUREMENTS AND RESULTS

In the reported experiments, the diffusion coefficient for two diffusants of the type n-(CH//2)//NX was measured, where N congruent 25, 45 and X is a suitable label; the matrix was linear polyethylene cooled at widely differing rates from the melt. The measuring technique used is a recently developed one based on infrared microdensitometry. The results indicate that these diffusants diffuse faster in the slowly cooled matrix, in marked contrast to the behavior of gaseous diffusants. They are in agreement with the predictions of the model developed in a previous paper (part I), in which the constraints imposed by interlamellar tie molecules on long diffusants were shown to be important.